Gun sales in Lebanon have tripled since the current standoff between the government and the Hizbullah-led opposition began, prompting concern that political factions are rearming.

The increased presence of gunmen on the streets of the capital, Beirut, and reports of fighters loyal to the Sunni-dominated government being trained overseas has heightened fears of a return to civil war, which ravaged Lebanon from 1975 to 1990. Gunfights last month, some involving the army, left six civilians dead and more than 150 wounded.

"There is a reappearance of arms in the hands of almost every political group; we are sitting on a powder keg, tension is increasing every day," said a prominent security analyst. "They don't know what they are doing, they are going to destroy this country."

A two-month campaign by the Shia and Christian opposition to topple the government descended into riots and street battles last month between Christians from rival camps and between pro-government Sunnis and the opposition.

The Arab League secretary general, Amr Moussa, is expected to visit Beirut soon in a second attempt to mediate after his efforts in December failed.

Tensions are running high ahead of the second anniversary next week of the assassination of Sunni prime minister Rafik Hariri, when supporters of the government intend to stage a massive rally near the sprawling tent city where opposition protesters have been staging a sit-in for more than eight weeks.

The sense of instability has deepened with the seizure of guns and training equipment in November from members of a former Christian militia commando unit as well as reports by US intelligence analysts of fighters loyal to Lebanon's largest Sunni party being trained abroad.

The private intelligence company Stratfor reported in December that "Lebanon's Sunni bloc, led by the Hariri clan and their regional Arab allies, has sent a number of fighters to Jordan, Saudi Arabia and Egypt to receive military training to counter Hizbullah's well-equipped and well-trained military forces."

According to the analyst...-...himself a Sunni...-...contingents of men are being brought from Sunni areas in the north to safe houses around the centre of Beirut where they are armed in preparation for clashes such as those last month.

"They are not militias yet but they are increasingly assuming the role of a militia," he said.

Hizbullah has said it wants to prevent violence, claiming any division will be exploited by Israel, but its significant military apparatus remains controversial among Lebanese.

According to one Lebanese newspaper, illegal arms sales have increased threefold. Lebanon is now awash with arms dealers, the newspaper reported, some selling 10 to 15 guns a day in a country of four million people. Many of the guns are bought by individuals, but there have also been newer weapons bought in bulk by supporters of key political groups.